1. Field of the Invention
This invention relates to a closed loop dispensing system and more particularly to a dispensing system for dispensing corrosive liquid chemicals or dangerous medical liquid products which are typically drawn from a container, such as a bottle or the like, to a mixing machine or the like.
2. Description of the Related Art
Corrosive liquid chemicals and dangerous medical liquid products are typically contained in a container such as a bottle or the like and are frequently dispensed therefrom to a mixing machine. Normally, a cap is placed on the bottle with a dip tube extending therefrom downwardly into the interior of the bottle for drawing the liquid upwardly thereinto. Normally, a dispensing tube extends from the cap to a mixing machine or to some other piece of equipment which creates suction in the dispensing tube to draw the liquid from the interior of the bottle. In some prior art devices, when the suction or vacuum is removed from the dispensing tube, backflow may occur. Further, when the cap is removed from the bottle, backflow from the dispensing tube may also occur. Additionally, when the cap is removed from the bottle, liquid residue in the bottle may spill therefrom. Additionally, the conventional prior art systems normally do not prevent the re-use of the bottle which is prohibited in some cases. Yet another disadvantage of the prior art is that a reliable and efficient venting means for the bottle is not normally provided for relieving vacuum pressure from within the bottle.